Kepler, Hubble and other space telescopes have pinpointed plenty of planets orbiting distant stars, but scientists' knowledge of them is still lacking.That's why in 5 years the European Space Agency plans to launch a new telescope to study these planets' size, mass and internal composition.

The new telescope, CHEOPS (CHaracterizing ExO PlanetS), will look for fluctuations in brightness of nearby stars to tell if something's orbiting them. It will play a huge part in figuring out the planets' mass and radius - the key variables to determining the planet's internal composition, figuring the kind of resources they can provide and help scientists learn more about how planets form. In particular, CHEOPS will scan nearby solar systems for planets that resemble Earth - with vegetation, oxygen/ozone in its atmosphere etc. This would help come up with a definitive answer about whether or not extraterrestrial life exists. According to Martin Rees, Britain's Astronomer Royal, we should know in a couple of decades whether or not such a planet exists anywhere near our solar system.

CHEOPS will orbit the Earth in sync with the sun at 500 miles above the planet's surface. The ESA currently plans to launch it sometime in 2017.